http://uploadpsd.com/file/53488.psdHere. A photoshop file with pen work so that you can expand it or reduce it to any size... I also added tabs to use with Glue instead of tape, because when i do it with tape, it gets pretty ugly in the end....

well you can use this http://www.instructables.com/file/FU02VBGFCEIJBNH/ I made a few some years ago for my girlfriend... btw it's called the shinsei mystery.. Don't know if you can see how it's supposed to be folded, but it's i bit more stable with the "struts" on the inside of the cubes instead of being hollow